Grinding machine



June 1, 1948. s. M. GREEN GRINDING MACHINE 2 Sheets-Sheet 1 Filed March 15, 1945 W W w u June 1, 1948. G. M, GRE N 2,442,683

' GR-INDING MACHINE Filed March 15, 1945 2 Sheets-Sheet 2 Patented June 1, 194% GRINDING MACHINE Glenn M. Green, Springfield, Vt., assignor to Bryant Chucking Grinder Company, Springfield, Vt., a. corporation of Vermont Application March 15, 1945, Serial No. 582,822

4 Claims.

1 In the grinding of taper holes, the smaller diameter end portion of the hole is of less circumference than the larger end portion, and

consequently for each complete rotation of the Work, less surface has to be ground. If a cylindrical grinding wheel is employed to grind this surface, both ends of the wheel rotate at the same peripheral speed, and as the grinding at the smaller end of the hole acts on a smaller area per unit of length than at the larger end, over-grinding of the smaller end is likely to result. Similarly when external taper grinding is produced with a cylindrical wheel, over-grinding of the smaller end is liable to occur.

This invention, therefore, has for one of its objects to provide a grinding machine having means for holding and rotating work about the axis of a tapered surface and to present a tapered grinding wheel to such surface with the taper of the wheel facing in the general direction of the taper of the surface, but with its periphery on one side of its axis parallel to the same side of the surface. This requires that the Work and the wheel spindle axes be out of line with the line of traverse, the latter being parallel to one side of the taper surface of the work.

This invention, therefore, has for a further object to provide a mounting for the work and a tapered wheel by which the desired relative motion may be effected. It is also found that with this arrangement of wheel and work a much improved surface finish of work is obtained.

A further object of the invention is to providefor relative feed motion between the work and grinding wheel substantially perpendicular to the axis of rotation of the spindle.

A further object is to provide for motion of the grinding wheel lengthwise and crosswise of the work axis.

The motions of the grinding wheel lengthwise and perpendicular to the Wheel axis make possible the substitution of a face grinding wheel in place of the internal wheel for truing off the face of the work perpendicular to its axis of rotation. This permits the grinding of the internal face and end face truin to be accomplished with a single chucking of the work piece so that the ground faces are maintained accurately in predetermined relation.

The grinding machine of this invention is therefore provided with work and wheel mountings adjustable to bring their rotational axes out of parallelism with the traverse directions, and at least one movable lengthwise and transverse to its own axis.

For a more complete understanding of this invention, reference may be had to the accompanying drawings in which Figure 1 is a fragmentary view partly in side elevation and partly in vertical section of an internal grinding machine embodying the invention.

Figure 2 is a fragmentary top plan of the same, a portion of the work and its holding chuck being shown in central horizontal cross section.

Figure 3 is a sectional view on line 33 of Figure 2.

Figure 4 is a somewhat diagrammatic view similar to Figure 2, but illustrating the direction of traverse for taper grinding and truing.

Figure 5 is a view similar to Figure 4, but illustrating traverse motion for face grinding and truing. 7

Referring first to Figures 1 to 3, at I is shown a machine bed on the upper face of which is carried a rotary work spindle 2 provided at one end with a work holder or support 3 indicated conventionally as a chuck. The spindle 2 is journaled in a bearing 4 and on its rear end may be provided with a pulley 5 over which a driving belt 6 may be passed, this belt also passing around the driving pulley l on the shaft 8 of a motor 9 mounted on a support It! which also carries the bearin '4. The support Ill may be adjustable angularly in a plane, for this purpose,the bed I being provided with a pair of arcuate tracks H and I2 having T slots I3 therein for the reception of suitable fastening devices by which the support 10 may be secured in adjusted position. A guide bar I5 is shown as extending out from beneath the upper face of the bed I and upon this guide bar [5 is mounted a carriage l6 movable therealong. The carriage I 5 has a supporting head 11 journaled thereon about a trunnion [B which depends from a slideway A second carriage 20 is mounted for axial motion on the slideway l 9, and as shown best in Figure 3, it may be provided with a nut portion 21 for engagement with a feed screw 22 extending longitudinally of the slideway l9 and journaled therein. As shown it has a hand wheel 23 at its outer end by which it may be turned, thus to move the carriage 20 longitudinally of the slideway l9, which, in turn, is angularly adjustable about the trunnion Ill.

The carriage 2B is provided with ways 23 disposed at right angles to the ways of the slideway 19, and slidably guided thereby is a wheel spindle carriage 25 having journaled therein a 3 wheel spindle 26 to which may be attached either a taper grinding wheel 21, as shown in Figures 2, 3 and 4, or a face grinding wheel 28, as shown in Figure 5. As shown in Figure 2, the work spindle 2 is adjusted in a horizontal plane angularly such that one side face of a. work piece 3|, having a tapered bore, lies in parallel relation to the axis, of the guide bar. 15. A tapered grinding wheel 21 carried bythe spindle 26 and of a corresponding taper to the taper bore of the work is, adjustable angularly by angular adjustment of the wheel spindle about the trunnion I8 so that one of its side faces is parallel to the side face 30 of the work bore,

both bein parallel to the axis ofthe guide bar I5. The grinding wheel is maintained in position to traverse the work throughout all the Bosh tions of angular adjustment of the spindle, the

adjustment selected depending upon the-taper of the wheel, for best results this being correlated with the taper of the hole being-ground.

By relatively moving the workspindleand wheel spindle in the direction of. the guide-bar 15, in the construction shown, the. wheel spindle being so moved by motion of the carriage l6 along the guide bar [5, the tapered grinding wheel may be caused to traverse the bore of..the work as shown in Figure ,4, thus to grind, the interior of the bore to thedesired taper. It will be noted that the larger diameterend; of the grinding wheel engages the larger diameter portion of the work, while the smaller diameter portion of the grinding wheel engages the smaller diameter portionof the work, and with the tapers substantially equal, it will be evident that the grinding effect of both end portions ofthe wheel on the work will be equalized, a slower moving end portion of the wheel engaging the slower moving surface portion of the work .at the smaller diameter. Thus thegrinding effect is substantially equalized throughout the, entire length of the work so that. no over-grinding of any portion is produced and a much. improved finishof the work is produced.

Feed of the grinding wheel with reference to the work may be produced by either axialor transverse motion of the Wheel spindle, each having a component transverse to the work. face. The axial motion may be produced by rotation of the hand wheel 23, while transverse motion may be produced by. rotation of the hand wheel secured toa feed screw 36, journaled inthe carriage 2G and threaded into a portion ("of the wheel mounting 25.

During traverse of the wheel its desired taper contour may be maintained by including in the traverse a truing device carried by an arm 4! pivotaily mounted on a horizontal shaft 42 carried by a stand 43. The pivotal mounting of the truing device on the pivot 42 permits the truing device to be swung back out of the way when it isdesired, or to beswung down so as to lie in the path of motion of the wheel when the latter is retracted from the work. The stand 43.may be pivoted about a vertical pivot so as to be turnable from the position shown in Figure 4 to the position shown in Figure 5 at rightangles thereto. When in the position shown in'Figure 5, the truing device 40 is presented, when it is swung downwardly, into position to true the end face 45 of the face truing-wheel 28, whenthis is substituted for'the taper grinding wheel 27.

Axial motion of the wheel spindle when the face truing wheel 28 is employed will act to move this wheel toward and'from theend-face-of the work as shown in Figure 5. Motion of the wheel spindle 26 transversely of its axis, as by turning the hand wheel 35, will cause this face grinding wheel to be moved between positions where it is effective to grind the outer face of the work, or where its grinding face passes across the truing device 40, thereby to true the wheel 28 for face grinding. With theaxes of the work spindle and the wheel in parallel relation, the face grinding is accurately produced. In this case the motion of the carriage I6 axially along the guide bar: l5-will serve to bring the face grinding Wheel toward and from the face of the work, but the actual feed of grinding is preferably produced ,byaxial motion of the spindle which is directly in line with the direction of feed desired.

From the, foregoing description of an embodiment of this invention, it should be evident to those-skilled in the art that various changes and modifications might be made without departing from its spirit orscope.

Iclaimt' l. A grinding machine comprising a. rotary worksupportand a-rotary grinding wheel spindle mounted for relative traversing motion, means for rotating said worksupport, means for rotate ing said grinding wheel spindle, means for ad justing said support andspindle angularly in a plane relative to the line of traverse whileeach is maintained in position for relative operative traverse, means for moving said spindle axially, and. means for moving said spindle laterally of its axis.

2. A grinding machine comprising a. rotary work support and a rotary grinding wheel spindle, said spindle :being mounted for traversin motion. relative to said work support, means for rotating said work support, means for rotating said grinding wheel spindle, means for adjusting said support and spindle angularly in a:plane relative to the. line of traverse while each is maintained in position for relative operative traverse, means for moving said spindle axially, and means for moving said spindle laterally of its axis.

3. A grinding machine, comprising a rotary work support, means for rotating said work support, a. rotary grinding-wheel spindle, means for rotating said spindle, means for relatively moving said support and spindle to cause a wheel on said spindleto traverse work on said work support, means for adjusting said work. support angularly to thereby adjustits. axis of rotation relative to the line of traverse, means for adjusting said spindle angularly in the plane. of angular adjustment of. said work support and while a. wheel on said spindle is maintained in operative traversing relation to work on said work support, means for relatively moving said support and spindle axially of said spindle, and means for relatively moving said spindle. and work support transverse to the axis of said spindle.

4. A grinding machine, comprising a rotary work support, means for. rotating said work support, a rotary grinding wheel spindle, means for rotating said spindle, means for movingsaid spindle to cause a wheel on said spindle to traverse work on said work support, means for adjusting said work support angularly to thereby adjust its axis of rotation relative to-the-line of traverse, means for adjusting said spindle angularly in the plane of angular adjustment of said work support and while a wheel onsaid spindle is maintained in operative'traversing relation to work on said work support, means for moving said spindle axially, and means for moving said spindle transverse to its axis.

GLENN M. GREEN.

REFERENCES CITED Number 6 UNITED STATES PATENTS Name Date Kimmel Jan. 6, 1925 Strickland Apr. 13, 1937 Johnson Dec. 13, 1938 Bigelow Jan. 3, 1939 Birkigt .Apr. 2, 1941 Arms Feb. 9, 1943 

